Nextcloud set up with https inspection and proxy by Checkpoint firewall

Hi all,
By any chance anybody here had ever tried to use nextcloud when https inspection and proxy by Checkpoint firewall is on the edge of the network?
I trusted Checkpoint certificate on my ubuntu, set proxy address in config.php and /etc/environment, configured Checkpoint to bypass my ubuntu from https inspection, but still not able to download apps from nextcloud app store (Curl 28).